|
|||||
|
|
Effect of Water Activity and Moisture Content on the Stability of Beet Powder Pigments |
|
| Authors: | E. COHEN ISRAEL SAGUY |
| Affiliation: | Author Cohen is affiliated with the Institute of Quality Control &Extension Services for the Food Industry, 76 Mazeh St., Tel Aviv 65789, Israel.;Author Saguy is affiliated with the Div. of Food Technology, The Volcani Center, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel. |
| Abstract: | The effect of water activity (“dry”– 0.84) and moisture content on the stability of beet pigments (betanine and vulgaxanthine I) was investigated in beet powder stored at 35°C. Pigment deterioration followed a first order reaction. Water activity and moisture content had a pronounced exponential effect on pigment stability. A decrease of approximately one order of magnitude in pigment stability was observed when aw was increased from 0.32 to 0.75. Storing the powder at aw of 0.12 or below resulted in practically no deterioration of the pigments over a period of several months. Profound differences in pigment stability were attributed to sorption hysteresis and system composition. |
| Keywords: | |